The violence followed clashes between government and rebel forces, the report says.

In all 232 civilians were killed with “some hung from trees and others burned alive in their homes”, the report adds.

A 14-year-old girl was quoted in the report as saying she would never forget the atrocities she had witnessed.

“How can I forget the sight of an old man whose throat was slit with a knife before being set on fire?” she said.

“How can I forget the smell of those decomposed bodies of old men and children pecked and eaten by birds? Those women that were hanged and died up in the tree?” the girl added.

The investigators found that about 120 girls and women were raped or gang-raped, and the victims included women who had recently given birth.

“I was still bleeding from labour, but one of the soldiers raped me. I kept quiet and did not resist as I saw other women being shot dead for refusing to have sex with the soldiers and youth,” a 20-year-old woman said.

South Sudan became independent in 2011. It has been wracked by civil war, which has seen ethnic cleansing and numerous atrocities, since 2013.

It began when President Salva Kiir fired his deputy Riek Machar, accusing him of planning a coup – an allegation he denied.